'Chronic pain is often defined, somewhat misleadingly, as “pain that extends beyond the expected period of healing.” In reality, once you’ve “gone chronic,” as Tracey puts it, pain is the disease, rather than a symptom. '

'Studies of twins suggest that our pain response is, in part, heritable, but there are close correlations between chronic pain and many other factors—gender, age, stress, poverty, and depression. '

'The man’s lawyers were planning to use brain-imaging data to show that the injuries had left him in chronic pain. '